948 resultados para Growth Strategy


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Globally, agriculture is being intensified with mechanization and increased use of synthetic fertilizers and pesticides. There has been a scaling up of production to satisfy the demands of supermarket distribution. Problems associated with intensification of production, trade globalisation and a larger market demand for greater volumes of fresh produce, include consumers' concern about pesticide residues and leaching of nutrients and pesticides into the environment, as well as increases in the transmission of human food-poisoning pathogens on raw vegetables and in fruit juices. The first part of this research was concerned with the evaluation of a biological control strategy for soil-borne pathogens, these are difficult to eliminate and the chemicals of which the most effective fumigants e.g. methyl bromide, are being withdrawn form use. Chitin-containing crustaceans shellfish waste was investigated as a selective growth substrate amendment in the field, in glasshouse and in storage trials against Sclerotinia disease of Helianthus tuberosus, Phytophthora fragariae disease of Fragaria vesca and Fusarium disease of Dianthus. Results showed that addition to shellfish waste stimulated substrate microbial populations and lytic activity and induced plant defense proteins, namely chitinases and cellulases. Protective effects were seen in all crop models but the results indicate that further trials are required to confirm long-term efficacy. The second part of the research investigated the persistence of enteric bacteria in raw salad vegetables using model food poisoning isolates. In clinical investigations plants are sampled for bacterial contamination but no attempt is made to differentiate between epiphytes and endophytes. Results here indicate that the mode isolates persist endophytically thereby escaping conventional chlorine washes and they may also induce host defenses, which results in their suppression and in negative results in conventional plate count screening. Finally a discussion of criteria that should be considered for a HACCP plan for safe raw salad vegetable production is presented.

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BACKGROUND: The conventional treatment protocol in high-intensity focused ultrasound (HIFU) therapy utilizes a dense-scan strategy to produce closely packed thermal lesions aiming at eradicating as much tumor mass as possible. However, this strategy is not most effective in terms of inducing a systemic anti-tumor immunity so that it cannot provide efficient micro-metastatic control and long-term tumor resistance. We have previously provided evidence that HIFU may enhance systemic anti-tumor immunity by in situ activation of dendritic cells (DCs) inside HIFU-treated tumor tissue. The present study was conducted to test the feasibility of a sparse-scan strategy to boost HIFU-induced anti-tumor immune response by more effectively promoting DC maturation. METHODS: An experimental HIFU system was set up to perform tumor ablation experiments in subcutaneous implanted MC-38 and B16 tumor with dense- or sparse-scan strategy to produce closely-packed or separated thermal lesions. DCs infiltration into HIFU-treated tumor tissues was detected by immunohistochemistry and flow cytometry. DCs maturation was evaluated by IL-12/IL-10 production and CD80/CD86 expression after co-culture with tumor cells treated with different HIFU. HIFU-induced anti-tumor immune response was evaluated by detecting growth-retarding effects on distant re-challenged tumor and tumor-specific IFN-gamma-secreting cells in HIFU-treated mice. RESULTS: HIFU exposure raised temperature up to 80 degrees centigrade at beam focus within 4 s in experimental tumors and led to formation of a well-defined thermal lesion. The infiltrated DCs were recruited to the periphery of lesion, where the peak temperature was only 55 degrees centigrade during HIFU exposure. Tumor cells heated to 55 degrees centigrade in 4-s HIFU exposure were more effective to stimulate co-cultured DCs to mature. Sparse-scan HIFU, which can reserve 55 degrees-heated tumor cells surrounding the separated lesions, elicited an enhanced anti-tumor immune response than dense-scan HIFU, while their suppressive effects on the treated primary tumor were maintained at the same level. Flow cytometry analysis showed that sparse-scan HIFU was more effective than dense-scan HIFU in enhancing DC infiltration into tumor tissues and promoting their maturation in situ. CONCLUSION: Optimizing scan strategy is a feasible way to boost HIFU-induced anti-tumor immunity by more effectively promoting DC maturation.

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Starvation during early development can have lasting effects that influence organismal fitness and disease risk. We characterized the long-term phenotypic consequences of starvation during early larval development in Caenorhabditis elegans to determine potential fitness effects and develop it as a model for mechanistic studies. We varied the amount of time that larvae were developmentally arrested by starvation after hatching ("L1 arrest"). Worms recovering from extended starvation grew slowly, taking longer to become reproductive, and were smaller as adults. Fecundity was also reduced, with the smallest individuals most severely affected. Feeding behavior was impaired, possibly contributing to deficits in growth and reproduction. Previously starved larvae were more sensitive to subsequent starvation, suggesting decreased fitness even in poor conditions. We discovered that smaller larvae are more resistant to heat, but this correlation does not require passage through L1 arrest. The progeny of starved animals were also adversely affected: Embryo quality was diminished, incidence of males was increased, progeny were smaller, and their brood size was reduced. However, the progeny and grandprogeny of starved larvae were more resistant to starvation. In addition, the progeny, grandprogeny, and great-grandprogeny were more resistant to heat, suggesting epigenetic inheritance of acquired resistance to starvation and heat. Notably, such resistance was inherited exclusively from individuals most severely affected by starvation in the first generation, suggesting an evolutionary bet-hedging strategy. In summary, our results demonstrate that starvation affects a variety of life-history traits in the exposed animals and their descendants, some presumably reflecting fitness costs but others potentially adaptive.

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We have examined the inter- and intra-group seasonal succession of 113 diatom and dinoflagellate taxa, as surveyed by the Continuous Plankton Recorder (CPR) in the North Atlantic, by grouping taxa according to two key functional traits: cell size (mg C cell21) and trophic strategy (photoautotrophy, mixotrophy, or heterotrophy). Mixotrophic dinoflagellates follow photoautotrophic diatoms but precede their obligate heterotrophic counterparts in the succession because of the relative advantages afforded by photosynthesizing when light and nutrients are available in spring. The mean cell size of the sampled diatoms is smallest in the summer, likely because of the higher specific nutrient affinity of smaller relative to larger cells. Contrastingly, we hypothesize that mixotrophy diminishes the size selection based on nutrient limitation and accounts for the lack of a seasonal size shift among surveyed dinoflagellates. Relatively small, heterotrophic dinoflagellates (mg C cell21 , 1023) peak after other, larger dinoflagellates, in part because of the increased abundance of their small prey during nutrientdeplete summer months. The largest surveyed diatoms (mg C cell21 . 1022) bloom later than others, and we hypothesize that this may be because of their relatively slow maximum potential growth rates and high internal nutrient storage, as well as to the slower predation of these larger cells. The new trait database and analysis presented here helps translate the taxonomic information of the CPR survey into metrics that can be directly compared with trait-based models.

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Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL/Apo-2L) has emerged as a promising anticancer agent. However, resistance to TRAIL is likely to be a major problem, and sensitization of cancer cells to TRAIL may therefore be an important anticancer strategy. In this study, we examined the effect of the epidermal growth factor receptor (EGFR)tyrosine kinase inhibitor (TKI) gefitinib and a human epidermal receptor 2 (HER2)-TKI (M578440) on the sensitivity of human colorectal cancer (CRC) cell lines to recombinant human TRAIL (rhTRAIL). A synergistic interaction between rhTRAIL and gefitinib and rhTRAIL and M578440 was observed in both rhTRAIL-sensitive and resistant CRC cells. This synergy correlated with an increase in EGFR and HER2 activation after rhTRAIL treatment. Furthermore, treatment of CRC cells with rhTRAIL resulted in activation of the Src family kinases (SFK). Importantly, we found that rhTRAIL treatment induced shedding of transforming growth factor-alpha (TGF-alpha) that was dependent on SFK activity and the protease ADAM-17. Moreover, this shedding of TGF-alpha was critical for rhTRAIL-induced activation of EGFR. In support of this, SFK inhibitors and small interfering RNAs targeting ADAM-17 and TGF-alpha also sensitized CRC cells to rhTRAIL-mediated apoptosis. Taken together, our findings indicate that both rhTRAIL-sensitive and resistant CRC cells respond to rhTRAIL treatment by activating an EGFR/HER2-mediated survival response and that these cells can be sensitized to rhTRAIL using EGFR/HER2-targeted therapies. Furthermore, this acute response to rhTRAIL is regulated by SFK-mediated and ADAM-17-mediated shedding of TGF-alpha, such that targeting SFKs or inhibiting ADAM-17, in combination with rhTRAIL, may enhance the response of CRC tumors to rhTRAIL. [Cancer Res 2008;68(20):8312-21]

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Attracting in-migration of the creative class has been argued by Florida (2002) to be a route to higher economic growth in the era of the knowledge economy. This paper critically evaluates this proposition in relation to old industrial regions using the example of Scotland. The paper presents an assessment of, in the first instance, to what extent there is a shortage of skilled, talented and entrepreneurial individuals and, in the second instance, whether a talent attraction strategy alone can hope to attract such people to Scotland. It is proposed that for most migrants the availability of appropriate economic opportunities is a prerequisite for mobility. However, despite uncertain evidence that place attractiveness is a catalyst to mobility among the so-called creative class, this is not a reason for dismissing talent attraction programmes. Instead it is argued that talent attraction programmes have the potential to contribute to old industrial economies, but their success will be greatest when talent attraction is carefully targeted and based on economic realities rather than the marketing of ethereal conceptions of place attractiveness.

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The detection of illicit growth promoter use during meat production within the European Union is reliant on residue testing which is a limiting factor on the number of animals which can be tested and consequently compromises the efficacy of testing procedures. The present study examined a novel detection strategy based on the profiling of plasma component concentrations in response to growth promoter administrations. Calves subjected to nortestosterone decanoate, 17 beta-oestradiol benzoate and dexamethasone were found to have altered urea, aminoterminal propeptide of type III procollagen and sex hormone binding globulin profiles in response to treatments. These findings demonstrate the potential of using the identification of perturbed profiles within a panel of biomarkers which cover a spectrum of biological activity to reveal growth promoter abuse.

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mRNA chimeras from chromosomal translocations often play a role as transforming oncogenes. However, cancer transcriptomes also contain mRNA chimeras that may play a role in tumor development, which arise as transcriptional or post-transcriptional events. To identify such chimeras, we developed a deterministic screening strategy for long-range sequence analysis. High-throughput, long-read sequencing was then performed on cDNA libraries from major tumor histotypes and corresponding normal tissues. These analyses led to the identification of 378 chimeras, with an unexpectedly high frequency of expression (˜2 x 10(-5) of all mRNA). Functional assays in breast and ovarian cancer cell lines showed that a large fraction of mRNA chimeras regulates cell replication. Strikingly, chimeras were shown to include both positive and negative regulators of cell growth, which functioned as such in a cell-type-specific manner. Replication-controlling chimeras were found to be expressed by most cancers from breast, ovary, colon, uterus, kidney, lung, and stomach, suggesting a widespread role in tumor development.

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In 1997 the Irish government adopted the National Anti-Poverty Strategy (NAPS), a global target for the reduction of poverty which illuminates a range of issues relating to official poverty targets. The Irish target is framed in terms of a relative poverty measure incorporating both relative income and direct measures of deprivation based on data on the extent of poverty from 1994. Since 1994 Ireland has experienced an unprecedented period of economic growth that makes it particularly important to assess whether the target has been achieved, but in doing so we cannot avoid asking some underlying questions about how poverty should be measured and monitored over time. After briefly outlining the nature of the NAPS measure, this article examines trends in poverty in Ireland between 1987 and 1997, Results show that the relative income and deprivation components of the NAPS measure reveal differential trends with increasing relative income poverty, but decreasing deprivation. However, this differential could be due to the fact that the direct measures of deprivation upon which NAPS is based have not been updated to take account of changes in real living standards and increasing expectations. To test whether this is so, we examine the extent to which expectations about living standards and the structure of deprivation have changed over time using confirmatory factor analysis and tests of criterion validity using different definitions of deprivation. Results show that the combined income and deprivation measure, as originally constituted, continues to identify a set of households experiencing generalised deprivation resulting from a lack of resources.

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We report on another alternative sensing platform for the detection of protein biomarker (PSA–ACT complex) based on homogenous growth of Au nanocrystals in solution phase. The immuno-recognition event is translated into the gold nanoparticle growth signal which can be intuitively recognized by an unaided eye, or quantitatively measured by an UV–vis spectrophotometric analysis. Surface plasmonic signature and kinetics of the Au nanogrowth in the homogenous phase containing of HAuCl4, AA, and CTAB have also been studied to provide suitable parameters for the immunoassay. As a result, detection limit of PSA–ACT complex was determined to be 10 fM. The result indicated that this is a very sensitive, robust, simple, and economic strategy to detect protein biomarkers, and it has great potential to detect other biological interactions.

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Au nanoparticles (AuNPs) have been widely used not only as optical labels or ‘weight” labels for the detections of biorecognition events but also an amplifier of surface plasmon resonance biosensors. The intrinsic property of gold nuclei composing of a group of Au atoms to catalyze the reduction of metal ions on the NPs and thereby to enlarge the metallic nanoparticles is employed in different biosensing paths. In a solution containing Au+ ions (e.g. HAuCl4) and the Au clusters, hydrated electrons which are reduced from oxidation of reducers (H2O2, sodium citrate, ascorbic acid, or NaBH4) will be used to reduce the Au+ ion leading to the deposition of Au+ to the Au0 (Au clusters). The reaction will be catalyzed continuously by the Au0 until the Au+ ions and hydrated electrons are exhausted. As a result, the AuNPs will be grown and their optical properties are also changed. If the AuNP nanoclusters are used as probes, the color change will be dependent on amount of analytes, thus give a quantitative monitoring of the analytes.

In this study, we incorporate the use of magnetic beads with the nanocrystalline growth to quantify a target protein based on immunoreactions. Prostate specific antigen (PSA) is chosen as the target analyte because of its values in diagnosis of prostate cancer. A double-sandwiched immunoassay is performed by gold-tagged monoclonal PSA antibody-PSA antigen – magnetic bead-tagged polyclonal PSA antibody interactions. After the immunoreactions, the target analytes are preconcentrated and separated by the magnetic beads while the nanogrowth plays a role of colorimetric signal developer.

The result shows that this is a very sensitive, robust and excellent strategy to detect biological interactions. PSA antigen is detected at femtomolar level with very high specificity under the presence of undesired proteins of crude samples. Furthermore, the method also shows great potential to detect other biological interactions. More details will be described in our presentation.

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Acute lung injury is a common, devastating clinical syndrome associated with substantial mortality and morbidity with currently no proven therapeutic interventional strategy to improve patient outcomes. The objectives of this study are to test the potential therapeutic effects of keratinocyte growth factor for patients with acute lung injury on oxygenation and biological indicators of acute inflammation, lung epithelial and endothelial function, protease:antiprotease balance, and lung extracellular matrix degradation and turnover.

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The discovery of underlying mechanisms of drug resistance, and the development of novel agents to target these pathways, is a priority for patients with advanced colorectal cancer (CRC). We previously undertook a systems biology approach to design a functional genomic screen and identified fibroblast growth factor receptor 4 (FGFR4) as a potential mediator of drug resistance. The aim of this study was to examine the role of FGFR4 in drug resistance using RNAi and the small-molecule inhibitor BGJ398 (Novartis). We found that FGFR4 is highly expressed at the RNA and protein levels in colon cancer tumour tissue compared with normal colonic mucosa and other tumours. Silencing of FGFR4 reduced cell viability in a panel of colon cancer cell lines and increased caspase-dependent apoptosis. A synergistic interaction was also observed between FGFR4 silencing and 5-fluorouracil (5-FU) and oxaliplatin chemotherapy in colon cancer cell lines. Mechanistically, FGFR4 silencing decreased activity of the pro-survival STAT3 transcription factor and expression of the anti-apoptotic protein c-FLIP. Furthermore, silencing of STAT3 resulted in downregulation of c-FLIP protein expression, suggesting that FGFR4 may regulate c-FLIP expression via STAT3. A similar phenotype and downstream pathway changes were observed following FGFR4 silencing in cell lines resistant to 5-FU, oxaliplatin and SN38 and upon exposure of parental cells to the FGFR small-molecule inhibitor BGJ398. Our results indicate that FGFR4 is a targetable regulator of chemo-resistance in CRC, and hence inhibiting FGFR4 in combination with 5-FU and oxaliplatin is a potential therapeutic strategy for this disease.

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This paper presents a novel strategy for the prevention of ventilator-associatedpneumonia that involves coating poly(vinyl chloride, PVC) endotracheal tubes (ET) withhydrogels that may be subsequently used to entrap nebulized antimicrobial solutions. Candidatehydrogels were prepared containing a range of ratios of hydroxyethyl methacrylate (HEMA) andmethacrylic acid (MAA) from 100:0 to 70:30 using free radical polymerization and, whenrequired, simultaneous attachment to PVC was performed. The mechanical properties, glasstransition temperatures, swelling kinetics, uptake of gentamicin from an aqueous medium, andgentamicin release were characterized. Increasing the MAA content of the hydrogels significantlydecreased the ultimate tensile strength, % elongation at break, Young’s modulus, and increasedthe glass transition temperature, the swelling ratio, and gentamicin uptake. Microbial(Staphylococcus aureus and Pseudomonas aeruginosa) adherence to control (drug-free) hydrogelswas observed; however, while adherence to gentamicin-containing p(HEMA) occurred, noadherence occurred to gentamicin-containing HEMA:MAA copolymers. Antimicrobialpersistence of gentamicin-containing hydrogels was examined by determining the zone ofinhibition against each microorganism on successive days. Hydrogel composition affected the observed antimicrobial persistence,with the hydrogel composed of 70:30 HEMA:MAA exhibiting >20 days persistence against S. aureus and P. aeruginosa,respectively. To simulate clinical use, the hydrogels (coated onto PVC) were first exposed to a nebulized solution of gentamicin(4 mL, 80 mg for 20 min), and then to nebulized bacteria (4 mL ca. 1 × 109 colony forming units mL−1, 30 min). Viable bacteriawere not observed on the gentamicin-treated p(HEMA: MAA) copolymers, whereas growth was observed on gentamicin-treatedp(HEMA). In light of the excellent antimicrobial activity and physicochemical properties, p(HEMA: MAA) copolymerscomposed of ratios of 80:20 or 70:30 HEMA: MAA were identified as potentially useful coatings of endotracheal tubes to be usedin conjunction with the clinical nebulization of gentamicin and designed for the prevention of ventilator-associated pneumonia

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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics